Administrative Core This Core will be directed by Dr. Wilson with Drs. Batshaw and Caplan serving as co-directors. The Core will provide basic administrative support to manage the financial operations of the program project to include oversight of accounts, purchasing, and preparation and submission of reports to the institution, as well as to the NIH. An External Scientific Advisory Committee (ESAC) will be convened, which will include scientists knowledgeable about areas relevant to the grant including immunology, urea cycle disorders, AAV and vector safety assessment. An Ethics Advisory Board (EAB) will also be convened and chaired by Dr. Caplan. This Board will include a scientist from the ESAC, as well as parents of children with inherited diseases and people with expertise in ethics, policy, and law. The ESAC and EAB will convene on an annual basis to review the progress of the science and help the team address important issues related to the ultimate clinical applications of gene therapy. Issues that will be considered by the EAB include target cell populations for early clinical trials, informed consent, inclusion and exclusion criteria, subject recruitment and communication with the community. The Core will also provide support in biostatistics from Dr. Robert McCarter.